Once described as “closer than lips and teeth,” Chinese relations with fraternal communist ally North Korea declined to the lowest level in decades this year, according to a draft congressional report.

“Sino-North Korean relations are at their lowest point in decades,” says the late draft of the annual U.S.-China Economic and Security Review Commission report.

“This is driven largely by China’s frustration over North Korea’s destabilizing behaviors since late 2012, including a nuclear test and a high volume of missile tests.”

Still, the report said Beijing regards the United States as its main threat in Northeast Asia, the report said and concludes that the regime of Kim Jong Un “has the potential to be one of the most dangerous flashpoints in U.S.-China relations.”

According to the commission report, based on hearings and interviews with government and private experts, North Korea is resentful of its dependence on China and views China as “high-handed and condescending.” The North Korean government also believes China has abandoned Marxism-Leninism and was corrupted politically and morally by capitalism.

“For its part, Beijing resents Pyongyang’s continued provocations, which it fears will destabilize and raise the risk of conflict in the region; drive South Korea and the United States to strengthen their alliance, and military capabilities, which also could be used to threaten China; and prompt the international community to criticize China for its role as North Korea’s primary supporter,” the report said.

The report concludes that despite the decline in relations, China will continue to support its ally and is being driven by fears of U.S. military power in South Korea.

High-level contacts between the two nations also have been limited in recent years.

When formally made public next month, the report will be the first time since 2002 the commission has included a chapter focused solely on China-North Korea relations. A copy of the draft was obtained by the Washington Free Beacon.

Regime collapse or a humanitarian disaster in North Korea appears unlikely in the near term but those events could lead to war that would likely include U.S., South Korea, and Chinese military forces.

Communications between those three countries is “dangerously insufficient to avoid accidents, miscalculation, and conflict in the event of military intervention in North Korea,” the report says.

North Korea has carried out a series of destabilizing actions in recent years, including torpedo and artillery attacks on a South Korea ship and military base, and three nuclear test and more than a dozen missile tests. However, in recent months the regime has been engaged in a diplomatic charm offensive designed to foster better international relations.

A diplomatic source familiar with intelligence reports said North Korea appears to be tilting its policies toward seeking increased support from Russia as a result of the decline in relations with China.

Pyongyang has been reaching out to Russia and other states in what the commission report called a sign of dissatisfaction with China.

Several trade deals were reached between North Korea and Russia in the past two years, including arrangements for more imports of Russian crude oil.

“This current upswing in Russia-North Korea relations reflects Pyongyang’s decades-long practice of adroitly playing its two patrons, China and Russia, against one another to extract political and economic gains and to mitigate the effects of international isolation,” the report said.

Despite China’s frustration with the Kim regime—the 30-year-old leader so far has not been permitted to visit Beijing—the Chinese are continuing to back North Korea in the interest of maintaining stability.

“China assesses that as long as the North Korean regime remains stable, North Korea will continue to exist as a buffer between itself and U.S.-allied South Korea,” the report says. “Preserving this buffer is the fundamental objective of China’s relationship with North Korea.”

The report was written before the mysterious disappearance of Kim from public view Sept. 3. U.S. officials say Kim suffered unspecified foot ailments.

Kim reappeared in state-run North Korean media reports Oct. 14 visiting a new housing complex for the country’s missile experts near Pyongyang. Analysts view the visit as a sign of the high priority the regime places on North Korea’s large-scale missile force.

North Korea maintains a large arsenal of missiles, including long-range Taepodongs and road-mobile KN-08s, medium-range Nodongs, and numerous short-range Russian-design Scuds. It also has exported missiles to Iran and Syria.

The disappearance triggered rumors that Kim was deposed in a coup, and that his sister, Kim Yo Jong, was running the totalitarian communist state.

U.S. intelligence agencies closely monitor North Korea and also have reported a decline in China ties. One report recently assessed that Pyongyang is actively taking steps seeking to reduce its reliance on China.

China failed to follow through on a $3 billion deal with North Korea to develop two piers at the far northern port of Rasin, and the Bank of China last year cut ties with the North Korean Foreign Trade Bank after the third nuclear test.

Asked about Kim’s disappearance, CIA spokesman Dean Boyd said in an email: “We have no comment for you!”

The China commission report notes that China increasingly regards U.S. activities on the Korean Peninsula as contrary to its interests.

“Beijing assumes Washington uses North Korean provocations as a pretext to bolster the U.S. military presence and capabilities on the Korean peninsula and justify a ‘rebalance’ policy that is actually aimed at containing China,” the report says.

Also, growing ties between China and South Korea are a Chinese signal of displeasure with North Korea, the report said.

China is continuing to provide oil, food, and military goods to its ally who was once described by Communist leader Mao Zedong as “closer than lips and teeth.”

“Most recently, in 2012, North Korea displayed transport-erector launchers for its new KN-08 ballistic missile affixed to vehicles imported from China,” the report said. “The Chinese government claimed the vehicles were ‘lumber transporters’ exported to North Korea in 2011 for agricultural use and stated the sale did not violate sanctions or Chinese law.”

China has not enforced United Nations sanctions on North Korea, and that has boosted the North’s military modernization and ballistic missile programs, the report said.

John Tkacik, a former State Department China specialist, said the draft report is misleading in characterizing current tensions between China and North Korea.

Tkacik said differences between Beijing and Pyongyang are more a result of major political purges in China, like the ouster of security czar Zhou Yongkang and military leader Xu Caihou who we both pro-North Korea.

North Korea’s purge of Jang Song Thaek, a key go-between with China, also diminished relations, he said.

“China took Jang’s purge with equanimity, but Beijing’s purge of Zhou and Gen. Xu this year—for reasons wholly unrelated to North Korea—no doubt left its bureaucracy a bit uneasy,” said Tkacik, with the International Assessment and Strategy Center.

Tkacik also took issue with the report’s suggestion that China-North Korea ties were strained over pressure from Beijing not to conduct a fourth nuclear test.

“Pyongyang has detonated three nuclear device between 2006 and 2013, and China basically has done nothing except ‘call for all sides to show restraint,’” Tkacik said. “It’s possible that China pressured North Korea not to explode another bomb this past May, but if so, one would think that any stresses in China-North Korea ties would have eased.”

Additionally, trade has sharply increased between the two communist states, despite rumors that China curbed exports of crude oil.

“The USCC draft report acknowledges that China has propped up North Korea’s entire economy for the past 20 years, and all evidence up to now is that it continues to do so,” Tkacik said.

The report also recommends that the Pentagon include more details on Chinese support to North Korea in its annual reports to Congress on North Korea.